One type of valve is a flexible, resilient, self-closing, slit-type valve that can be mounted at an opening or port of a package or container of a fluent substance, or alternatively mounted within a conduit for a fluent substance. Such valves typically have a single slit or have multiple slits which define a normally closed orifice in an initially closed configuration or condition. The orifice opens to permit flow therethrough in response to either a sufficient pressure differential acting across opposite sides of the valve, or in response to mechanical engagement by a sufficiently rigid article such as a probe, cannula, conduit, or feed/drain tool inserted through the valve. Such valves that open in response to a pressure differential are typically designed so that they automatically close to seal or shut off flow therethrough in response to a sufficient reduction of the pressure differential acting across the valve. Similarly, mechanically engageable valves are typically designed so that they automatically close to seal or shut off flow therethrough upon removal of the engaging article.
A conventional valve 20 is shown in FIGS. 1-6, for use in a container of a fluent substance (not illustrated). The valve 20 is flexible, resilient, pressure-openable, self-closing, and of the slit-type. Forms of such a type of valve 20 are disclosed in the U.S. Pat. Nos. 5,839,614 and 8,678,249. The descriptions of those patents are incorporated herein by reference thereto to the extent pertinent and to the extent not inconsistent herewith.
The conventional valve 20 is suitable for use with fluent substances, such as liquids and gases, including, inter alia, beverages, lotions, and creams. The conventional valve 20 is preferably molded as a unitary structure (i.e., one-piece structure) from a single substance or material which is flexible, pliable, somewhat elastic, and resilient. This can include elastomers, such as a synthetic, thermosetting polymer, including silicone rubber, such as the silicone rubber sold by Dow Corning Corporation in the United States of America under the trade designation D.C. 99-595 and RBL-9595-40. Another suitable silicone rubber material is sold in the United States of America under the designation Wacker 3003-40 by Wacker Silicone Company.
The conventional valve 20 has an initially “closed”, unactuated, substantially unstressed, rest condition or position, and can be forced to an “open” position or condition (not illustrated) when a sufficiently high pressure differential acts across the valve 20, or when the valve 20 is engaged by a probe or other sufficiently rigid article.
With reference to FIG. 5, the conventional valve 20 has a first side surface 22 and a second side surface 24. In one known application, the first side surface 22 faces an interior of a fluent substance container and the second side surface 24 faces an exterior, ambient environment.
The conventional valve 20 has a peripheral attachment portion or mounting flange 26. The peripheral portion 26 is for being mounted or attached to a container of a fluent substance. Typically, this may be achieved through a retention structure or ring (not illustrated) that can mate with a feature on the container (not illustrated) on which the valve 20 may be installed.
Still referring to FIG. 5, extending laterally inwardly from the peripheral attachment portion 26 is a generally annular, intermediate portion or sleeve 28 that connects the peripheral attachment portion 26 to a head portion 30. The head portion 30 is flexible and resilient. As can be seen in FIG. 3, the head portion 30 has a generally circular configuration in plan view. The peripheral attachment portion 26, intermediate portion 28, and head portion 30 are oriented in a generally circular configuration and concentric relationship about a central axis 31 (FIGS. 4 and 5). A fluent substance can be dispensed (i.e., discharged) through the conventional valve 20 in a discharge flow direction generally along the axis 31 when the valve 20 opens. A probe can also be used to engage and open the valve 20 (not illustrated in FIGS. 1-6).
With reference now to FIG. 3, the head portion 30 has a normally closed orifice defined by a pair of intersecting, major slits 32 radiating laterally or radially from the center of the head portion 30. The head portion 30 further has a plurality of minor slits 36 branching from the radially outward ends of each one of the major slits 32. Each of the major slits 32 and the minor slits 36 extend transversely, fully through the thickness of the head portion 30 from the first side surface 22 to the second side surface 24.
The major slits 32 define four, generally pentagonal-shaped, equally sized openable portions or major petals in the valve head portion 30. The minor slits 36 define four, generally triangular-shaped, equally sized openable portions or minor petals in the head portion 30. Each major petal has a plurality of transverse faces defined by the major slits 32, and two of such transverse faces are visible in FIGS. 5 and 6. As can be seen in FIGS. 1-6, each such transverse face seals against a confronting transverse face of an adjacent major petal when the conventional valve 20 is closed.
Likewise, each minor petal has a pair of diverging transverse faces defined by the minor slits 36, and each transverse face seals against a confronting transverse face of an adjacent minor petal when the conventional valve 20 is closed. Forms of such types of slits and petals are disclosed in the U.S. Pat. No. 8,628,056. The description of that patent is incorporated herein by reference thereto to the extent pertinent and to the extent not inconsistent herewith.
The conventional valve 20 illustrated in FIGS. 1-6 can be opened in a number of ways. For example, a probe (such as the probe 102 illustrated in FIGS. 14 and 15 for a different valve), cannula, feed/drain tool, or other rigid article can be pushed against either side of the head portion 30 and through the head portion 30 so that the openable portions deflect to accommodate penetration by the probe. The conventional valve 20 can alternatively open when it is subjected to a sufficient pressure differential (e.g., a higher pressure on the first side 22 of the head portion 30 than on the second side 24 of the head portion 30, or vice versa).
The inventors of the present invention have discovered that, at least in some applications, a conventional valve (such as the valve 20 illustrated in FIGS. 1-6) may prematurely open and/or a fluent substance may undesirably leak through the valve after the initially closed valve is installed on a container or other type of fluent substance-containing system. Various fluent substances or products (including oils, lotions, creams, gels, liquids, food items, pharmaceuticals, granules, powders, etc.) may be packaged in a rigid, flexible, or collapsible container or contained within a system. Premature, inadvertent, or unplanned ingress or egress of a fluent substance through the valve may result in contamination of a product on one side of the valve or may result in premature or unwanted loss or release of the product from the system. Such instances of ingress or egress may occur during shipping, handling, sterilization, or storage of a container on which the valve is installed (especially if, for example, the container is subjected to impact, heating (such as during pasteurization), or other pressure increasing or decreasing conditions on one side of the valve).
The inventors of the present invention have determined that for at least some applications in which some types of fluent substances are contained within a package or container, it may be desirable to provide an improved valve that can eliminate, or at least reduce or minimize, the above-described, undesirable, premature valve opening events and/or ingress or egress leakage events.
The inventors of the present invention have considered that preventing leakage through, or premature opening of, a slit valve may be effected with a valve having an initially closed slit that is fully or partially sealed or coated on at least one side of the valve so as to leave a frangible coating that must be broken to initially open the valve. While such a coated valve can work well for its intended purposes in some applications, the inventors of the present invention have discovered that such a coated valve may not be desirable in some other applications for reasons relating to cost, manufacturing complexity or difficulty, operation, etc. The inventors of the present invention have discovered that for at least some applications, it would be desirable if at least some portion of a valve can be provided with an improved structure that can initially seal, maintain, or constrain the valve operable portions in a closed position or condition until the structure is ruptured during an initial opening process of the improved valve.
The inventors of the present invention have further determined that for at least some applications in which an article such as a probe, cannula, conduit or feed/drain tool is inserted through a valve, it may be desirable to provide a valve having both (1) improved sealing properties described above, and (2) a minimally increased opening force necessary to initially open the valve, when compared to the opening force of a conventional or prior art valve.
The inventors of the present invention have also determined that it would be desirable to provide, at least for one or more types of applications, an improved valve that can be configured for use with a fluent substance container so as to have one or more of the following advantages: (1) ease of manufacture and/or assembly, (2) relatively low cost of manufacture and/or assembly, (3) reduced unit-to-unit variability of the required initial valve opening force exerted by an engaging article or pressure differential, and (4) accommodation of the manufacture of the valve by means of efficient, high-quality, large-volume techniques with a reduced product reject rate to produce valves with consistent operating characteristics.
The inventors of the present invention have discovered how to provide such a valve that includes novel, advantageous features not heretofore taught or contemplated by the prior art, and which can accommodate designs having one or more of the above-discussed benefits or features.